Needle threading device



Mmh 22, 1955 C. J. M. BENINK ET AL v NEEDLE THREADING DEVICE Filed Aug.2l, 1952 6 Sheets-She@I l nvemons @mh 22, i955 c. J. M. BENINK ET Al.

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March 22, 1955 c. J. M. BENINK ET AL NEEDLE THREADING DEVICE 6Sheets-Sheet 6 Filed Aug. 21, 1952 innen/ons @y www United States PatentAv() NEEDLE TrmEADlNG DEVICE Christian Josef Marines Benink, HeinrichBungert, Emil Clauss, Ludwig Meissler, Herbert Schumann, and AlfredSchuster, Kaiserslautern, Germany, assignors to G. M. Pfaff A.G.,Kaiserslautern, Germany Application August 21, 1952, Serial No. 305,674

7 Claims. (Cl. 112-225) The present invention relates to threadingdevices f or sewing machines, particularly to a threading device whichcan be conveniently and simply manipulated.

The threading devices for sewing machines known heretofore were notemployed in actual practice because their form of construction was inmost instances too involved. As a rule the operation vrequired severalmanual operating members.

Thus a threading device is known which is mounted on the head of thesewing machine and operatively connected with the gear, which isintended to make possible the threading of torn threads in any positionof the needle bar. Furthermore, a threading device has been known wherea guiding bar which is axially and rotatably movable is mounted in thebore for the needle bar. The bar is pulled down until the height of theear of the needle is reached. Then the threader is swung manually intothe ear of the needle and the threading is undertaken. A spring whichsnaps into a groove of the needle bar serves for the correct alignmentof the threader relative to the ear. This operation requires themanipulating of two manual operating members.

It is the object of the invention to find a way to overcome the aboveditiiculties and a new solution which meets all the requirements for theconstruction of a threader. The threading device in accordance with theinvention not only avoids the disadvantages of the devices knownheretofore but has many important advantages over them, particularlythat of easy manipulation and great safety and reliability of operation.

The new device is provided at the head of the sewing machine andconsists of an axially and rotatably movable bar with a threaderprovided at the lower endthereof in the form of a hook or a notchedneedle. This bar is so disposed and guided that upon being shifteddownwardly by means of an; operating member it automatically eifects theswinging movement which brings the threader through the ear of theneedle at a predetermined height. For this purpose the swingingmovements of the bar are guided by suitable means, for example, by usinga curved groove. One or several springs make possible the automaticreturn of the threader to its free position after each threadingoperation.

For the operation of the threader in any desired position, suitablywithin a limited range above the presserfoot bar the guiding bar is inoperative relationship with the needle bar by means of a rod or the lke,which abuts the needle bar socket or the upper end of the needle bar.

The mechanical portion of the device is provided on the head of thesewing machine while in the position of rest only the threader isdisposed closely adjacent the lower portion of the head and theoperating member on the outside of the head. As compared with devicesknown heretofore the sewing operations are thus not disturbed becausethe sewing space is free of obstacles. The principal advantage of theinvention resides in that in threading a single operative step isundertaken and the return of therthreader to the starting position takesplace automatically under the effect of a spring.

The operation can be undertaken from any desired position. Thus theoperating member, for example, a lever or a push button may be arrangedwithin reach either above, below or laterally of the sewing machine.

Since it may happen that with the lever pressed down the hook isalready'in the ear of the needle and the machine is put in operation byinadvertent touching of the starter in electrically operated machines orof the treadle in non-electric machines, the abutment member, forexample the rod mentioned above, which is provided on the guiding barfor producing the coordination or the operative engagement with theneedle bar can be guided still further in accordance with the inventionduring its swinging movement by a track provided along the abutmentplane which may be constituted by a slot or a groove so that also insuch cases the hook is moved out of the ear of the needle without damageas a result of the controlled guidanceof the rod or the like.

Also the automatic control of the threader obtained by such a controlledguidance is of particular advantage if the needle bar is outside of thelimited range within which the threader is alone able to operate. Such asituation arises when the person operating the sewing machine is unableto accurately recognize the lower and upper limits of this range or whenthe lighting conditions are unfavorable. Thus the lever may be presseddown without paying attention to the position. It is merely necessary toslightly turn the machine onward. Only at the time when the exactadjustment of the threader with respect to the needle ear is attainedthe threader swings automatically into the ear and the threading can beeffected. The operation of the threading device is thus substantiallyfacilitated without particular requirements being necessary as to thedexterity of the person sewing.

As the controlled guiding track for the pin or the like a plate may beprovided on the needle bar socket, for example of angular shape, inwhich manner a slot or the like is formed between the plate and the topside of the socket for guiding the pin, which upon operation of theoperating lever for the guiding bar establishes operative connectionwith tlie needle bar. The pin or the like then no longer rests freelyand openly upon the needle bar socket but is given guidance in the slotby means of the plate. It is thus achieved that with the up and downwardmovement of the threader the pivoting movement of the threader is alwaysinsured.

In accordance with another form of such a guiding track this arrangementmay be mounted at a distance from the needle bar socket as anindependently adjustable element for example, in the form of a ring, adisc or the like von the needle bar proper. Such an embodiment offersadditional advantages with respect to the foregoing arrangement andpermits in the simplest manner an adjustment of the differences indistance between the needle bar lug and the needle ear. This differencecan be caused by increases in the length of the needle and in theposition of the ear of the needle. On the other hand, however, thethreader must be in exact alignment with the ear of the needle when inoperative position. The adjustment by moving the hook carrier by meansof set screws requires a certain skill not possessed by everyone. Ascompared to that, no particular adaptability is necessary to move thering or the like along the needle bar until the alignment of thethreader with the ear of the needle is reached. For such purposes theset screws need only be loosened on this ring and tightened again afterthe adjustment is made.

The invention is illustrated in the drawings in several embodimentswhere:

Figs. 1-3 show a threading device on a sewing machine having a needlebar guided in fixed bearings with the ear of the needle disposedtransversely to the direction of sewing and where the threading deviceis provided laterally of theneedle bar, with Fig. l showing particularlya front view of the head, Fig. 2 the operative connection of the barwith the needle bar lug and Fig. 3 the end with the protective shieldremoved;

Figs. 4-6 illustrate the position of the hook in various steps of thethreading operation; Figs. 7-.11 show the device partly in perspectiveview in connection with a sewing machine having an oscillating needlerod, the needle ear of which is disposed in the direction of sewing andwhere threading can be effected only with the bar in the highestposition, and the operation of which is by pulleys;

Figs. 12 -14 show a perspective view of several steps of the threadingoperation;

Fig. 15 shows a sewing machine with oscillating needle bar of the sameconstruction as above where the threading can be eiected in any desiredposition above the pressure foot;

Figs. 16-18 illustrate a front, side and top view of the controlledguiding of the abutment element (pin) upon a ring which is adjustable onthe needle bar;

Figs. 19-21 show a modified form of the controlled guidance by means ofan angular plate secured to the needle bar lug also in front, side andtop view; n

Figs. 22-24 show the hook with protective shield strip on the bar in afront view, plan view and cross section.

The bar 2 is guided in upper and lower bores in the head 1 of the sewingmachine at the lower end of which a clamp 3 is fastened by means of thescrew 4 which simultaneously holds the hook 5 besides the reinforcementplate 6 on the clamp 3. The sliding member 7, of sheet metal, is bent atright angles inwardly at the top and at the bottom. The bar 2 is passedthrough the bores in the two angle arms 8, 9. At the lower angular'member 9, the lug 10 is provided which is guided in the slot 11 providedin the plate 14 secured to the head-1 o f the machine by means of screws12, 13. A pin rigidly mounted in and extending through bar 2 is providedthe front part of which is disposed and guided in a grooved track 16 ofthe sliding member 7 and the back portion of which provides theoperative connection with the socket 17 of the needle bar. The pressurespring 18 which at its lower end rests against the head and at its upperend against the sliding member 7 provides for the returning of the bar 2while the pressure spring 19, supported against the pin of the bar andresting at the top against the sliding member 7 tends to press the bar 2downwardly. The operating lever 2t) on the sliding member 7 projectsthrough the aperture 21 in the head 1 of the sewing machine.

The threading device operates as follows:

When pressing downwardly on the lever sliding member 7 and the bar 2 aremoved downwardly against the force of pressure spring 18 until the pin15 abuts the needle bar socket 17. In this position the hook 5 isaligned at the same level with the ear of the needle 23. Furtherpressing on the lever 20 causes bar 2 to be moved by the front part ofthe pin 15 which is disposed in the grooved track 16, thus causing therotation with simultaneous swinging of the hook 5 into the ear of needle23. The hook in this case is moved from the right to the left. Thethread 24 is put on and the lever 20 is released somewhat. The bar 2swings back under the effect of spring 18 thus pulling the thread 24through the ear whereupon it is manually removed from the hook 5. Lever20 is now completely released causing the bar 2 with hook 5 to beautomatically returned by pressure spring 8 to the starting position.

In the sewing machine having an oscillating needle bar in accordancewith Figs. 7-11 the threading arrangement is secured to the needle baroscillator 25 by means of screws. The supporting member comprises anopen shell 26 in which the sliding member 27 is disposed for axialmovement. The shell 26 is provided with a lug 28 which is securelyfastened to the needle bar oscillator 25 by means of screws 29. Afurther lug 30 is bent around the needle bar oscillator 25 in order toprovide support for the upper portion of the supporting member. In theshell which is formed as a unitary structure with the sliding member 27the bar 31 is rotatably guided (see Fig. l0). The little arm 32 formedas a clamping member and having a hook 33 is secured to its lower end.Arm and hook are manufactured by a precision casting method. The hook 33may also be made of sheet metal bv stamping. In the shell 26 moves thesliding member 27 which is provided with the grooved track 34 forguiding the pin 35 of the bar 31. The pin 35 during the downwardmovement of the sliding member 27 and of the bar 31 results inengagement of pin 35 with lug 36. At this point the hook 33 and the earof the needle 37 are at eoual height if the needle bar is in itsuppermost position. Further pressure on member 27 results in pin 35following the track 34, thereby rotating the bar 31. ln the upperportion of the sliding member 27 bolt 38 is arranged as a shouldermember for the spring 39 which at its lower end rests against the bar31. Spring 39 is compressed when pin 35 engages lug 36 and member 27continues to move downwardly. A pulling spring 40 is fastened by meaensof ring 41 to the Sliding member 27 while at its upper portion it isclamped to the shell 26 by means of ring 42. The end of a pulling cord43 is secured to the sliding member 27, the cord being brought aroundthe return roller 44 upwardly along the three rollers 45 over roller 46and secured to the guiding member 26 at the top. A bolt 48 with apressing button 49 is provided on the protective shield 47. The spring50 presses the bolt and button outwardly. On the inside of theprotective shield 47 a bifurcated pusher member 51 is provided, the twoarms of which press on the cord 43 between rollers 45 upon pushisng onthe button 49 thus causing downward movement on the sliding member 27and the bar 31. The operation of the threading is shown in Figs. l214and described in connection with the preceding embodiment.

The needle threading device in accordance with Fig. l5 is fundamentallysimilar in construction and operation to the previously described deviceaccording to Figure 1, but here the device is associated with anoscillating needle bar. It also provides for threading in any desiredposition of the needle bar. The device is fastened to the needle baroscillator 52 in a manner that the two bearings 53, 54 for the bar 55are made in one piece with the needle bar oscillator 52. The lowerpressure spring 56 is not arranged inside the head due to lack of spacebut is disposed upon the clamp member 57 and at the top it rests againstthe lower portion of the bearing.

The sliding member 58 is elongated towards the bottom and ends in theoperating lever 59 with the bent end 60. Sliding member 58 and operatinglever 59 thus form a unitary structure. The operating lever 59 differsfrom the first embodiment in that it is provided at the bottom. Thelever 59 is moved manually downwardly and thus the sliding member 58 ispulled and not pressed. For the safe guiding the sliding member 58 isbent over at its left side and besides it is guided by the bar 55 whichslides in the two bores of the sliding member 58 which is bent at thetop and at the bottom.

A pin 15 extends through bar 55 resting with one end in guiding slot 16.When moved downwardly pin 15 strikes a at abutment on a member which isstationary relative to the bar 55, and continued downward pull on thebar 58 causes the pin to follow the slot 16, thereby rotating the bar55. The arrangement may be as illustrated in Figs. 16 to 18.

In accordance with Figs. 16-18 a ring 64 or the like is secured to theportion of the needle bar 61 disposed above the needle bar socket 17 bvmeans of two set screws 62, 63. The ring member 64 is provided with aslot 65 to present a guide track in which pin 15 of the guide bar 2 isguided when the pin 15 executes its rotary movement after the alignmentof the threader 5 (Figs. 22-24) with the ear of the needle bv way of theaforementioned grooved track. The pin. 15 together with the bar 2 whichcarries the threader 5 can move vertically upwardly or downwardlv beforeor after the swinging movement when it has disengaged the guiding slot65.

In the modified embodiment of a guide track illustrated in Figs. 19-21 aplate 66, for example of angular shape is provided upon the needle barsocket proper to constitute the guiding slot for the pin 15. At adistance corresponding to the thickness of the pin 15 an intermediatemember 67 is provided for that purpose above the upper end of the needlebar socket 17. At the lower end of the bar 2 a clamp member 70 isprovided as a carrier arm for the threader 5, which member is axiallymovable upon the bar. This clamp member 70 is secured to the bar 2 bymeans of screws 68, 69 (Figs. 2, 23). Two protective shield strips 72,73 are fastened to this clamp with a screw 71 together with the hook 5of the threader. These protective shield strips 72, 73 are somewhatsplit apart at the free front ends as clearly shown in Fig. 24.

In sewing machines having an oscillating or pendant needle bar thedevice is mounted on the needle bar oscillator or connected with it.This obtains that the distance of the threader remains always the samein any position which deviates from the vertical and the threadingoperation is not affected thereby. The device can also be installed insewing machines which were not originally provided with it.

Having now described our invention, what we claim is:

l. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye,

said device comprising a guided bar disposed adjacent said needle barand movable relatively thereto, a pm carried by said guided bar andprojecting outwardly therefrom, an arcuated threading element carried bysaid guided bar proximate the needle supporting end of said needle bar,an actuating mmber mounted adjacent to and in operative engagement withsaid guided bar for sliding movement and presenting an operating arm formoving said actuating member and said guided bar relative to said needlebar, abutment means disposed in the path of travel of said pin forengagement by said pin and presenting a shoulder at a prdetermineddistance from the eye of the needle to limit downward movment of saidguided bar, a guiding track defined in said actuating member havingengagement with one end of said pin and spring means supported at afixed point relative to said guided bar and said actuating member forbiasing said guided bar and said actuating member in inoperativeposition, whereby pressure on said arm first moves said actuating memberand said guided bar axially to establish engagement between said pin andsaid shoulder and align said threading element with the eye of theneedle, and continued pressure causes sliding movement of said pin onsaid track and on said shoulder, thereby rotating said guided bar andcausing said threading element to engage the eye of said needle.

2. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye, said device comprising a guided bar disposedadjacent and parallel to said needle bar and movable relatively thereto,a pin carried by said guided bar and projecting outwardly therefrom, anarcuated threading element carried by said guided bar proximate theneedle supporting end of said needle bar, an actuating member mountedaround and in operative engagement with said guided bar for slidingmovement and presenting an operating arm for manually moving saidactuating member and said guided bar longitudinally relative to saidneedle bar, abutment means mounted on said needle bar in the path oftravel of said pin and presenting a shoulder for engagement by said pinat a predetermined distance from the eye of the needle to limit axialdownward movement of said guided bar, a guiding track defined in saidactuating member having engagement with one end of said pin and springmeans supported at a fixed point relative to said guided bar and saidactuating member for biasing said guided bar and said actuating memberin inoperative position, whereby pressure on said arm first moves saidactuating member and said guided bar axially to establish engagementbetween said pin and said shoulder and align said threading element withthe eye of the needle, and continued pressure causes sliding movement ofsaid pin on said track and on said shoulder, thereby rotating saidguided bar and causing said threading element to engage the eye of saidneedle.

3. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye, said device comprising a guided bar supported bythe needle bar oscillator adjacent and parallel to said needle bar andmovable longitudinally relatively to said needle bar, a pin carried bysaid guided bar and projecting outwardly therefrom, an arcuatedthreading element carried by said guided bar proximate the needlesupporting end of said needle bar, an actuating member mounted aroundand in operative engagement with said guided bar for sliding movementand presenting an operating arm extending outside the machine head formanually moving said actuating member and said guided bar longitudinallyrelative to said needle bar, abutment means mounted on said needle barin the path of travel of said pin having a set screw for adjustment onsaid needle bar and presenting a shoulder for engagement by said pin ata predetermined distance from the eye of the needle to limit axialdownward movment of said guided bar, a guiding track defined in saidactuating member having engagement with one end of said pin and helicalspring means around said guided bar supported at a fixed point relativeto said guided bar and said actuating member for biasing said guided barand said actuating member against said needle bar oscillator ininoperative position, whereby pressure on said arm first moves saidactuating member and said guided bar axially to establish engagementbetween said pin and said shoulder and align said threadingy elementwith the eye of the needle, and continued pressure causes slidingmovement of said pin on said track and on said shoulder, therebyrotating said guided bar and causing said threading element to engagethe eye of said needle.

4. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye, said device comprising a guided bar supported inthe machine head adjacent said needle bar for sliding movement, a pincarried by said guided bar, and projecting outwardly therefrom, anarcuated threading element carried by said guided bar proximate theneedle supporting end of said needle bar, an actuating member mountedaround and in operative engagement with said guided bar for slidingmovement and presenting an operating arm for moving said actuatingmember and said guided bar relative to said needle bar, abutment mentsdisposed in the path of travel of said pin and presenting a shoulder forengagement by said pin mounted on said needle bar at a predetermineddistance from the eye of the needle to limit axial downward movement ofsaid guided bar, a guiding track defined in said actuating member havingengagement with one end of said pin and spring means supported at afixed point relative to said guided bar and said actuating member forbiasing said guided bar and said actuating member in inoperativeposition, whereby pressure on said arm first moves said actuating memberand said guided bar axially to establish engagement between said pin andsaid shoulder and align said threading element with the eye of theneedle, and continued pressure causes sliding movement of said pin onsaid track and on said shoulder, thereby rotating said guided bar andcausing said threading element to engage the eye of said needle. i

5. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye, said device comprising a guided bar lsupported inthe machine head adjacent said needle bar for sliding movement, a pincarried by said guided bar and projecting outwardly therefrom, anarcuated threading element carried by said guided bar proximate theneedle supporting end of said needle bar, an actuating member mountedaround and in operative engagement witljrsaid guided bar for slidingmovement and presenting an operating arm for moving said actuatingmember andg'said guided bar relative to said needle bar, abutment meansdisposed in the path of travel of said pin presenting a shoulder forengagement by said pin mounted on said needle bar at a predetermineddistance from the eye of the needle to limit axial downward movement ofsaid guided bar, a guiding track defined by a slot extending obliquelyof said actuating member and having engagement with one end of said pin,and spring means biased against the lower end of the machine headholdingvl said guided bar and said actuating member in inoperativeposition, whereby pressure on said arm first moves said actuating memberand said guided bar axially to establish engagement between said pin andsaid shoulder and align said threading element with one eye of theneedle, and continued pressure causes sliding movment of said pin insaid slot and on said shoulder thereby rotating said guided bar andcausing said threading element to engage the eye of said needle.

6. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye at its lower end said device comprising a guidedbar disposed adjacent and parallel to said needle bar and movablerelatively thereto, a pin extending transversely of said guided bar andprojecting outwardly therefrom, an arcuated threading element carired bysaid guided bar proximate the needle supporting end of said needle barand having a hook adapted to enter the eye of the needle, actuatingmeans including a guiding member mounted around and in operativeengagement with said guided bar provided with an obliquely extendingslot to receive one end of said pin and with manual operating meanspresenting a member projecting from said machine head for moving saidguided bar longitudinally of said needle bar and said pin in said slot,abutment means presenting a shoulder in the path of travel of said pinat a predetermined distance from the eye of the needle to limitdownwardmovement of said guided bar and spring means extending between afixed point in said machine head and said actuating means for biasingsaid actuating means and said guided bar in inoperative position.

7. A needle threading device for a sewing machine of the type having areciprocating needle bar disposed in the machine head and supporting aneedle having an eye at its lower end, said device comprising a guidedbar disposed adjacent and parallel to said needle bar in a channelshaped member rigidly supported in said machine head and movablerelatively to said needle bar, a pin extending transversely of saidguided bar and projecting outwardly therefrom, an arcuated threadingelement carried endwise of said guided bar proximate the needlesupporting end of said needle bar and having a hook adapted to enter theeye of the needle, actuating means including a guiding member mounted insaid channel shaped member around and in operative engagement with saidguided bar and provided with an obliquely extending slot to receive oneend of said pin and with manual operating means presenting a memberprojecting from said machine head formoving said guided barlongitudinally of said needle bar and said pin in said slot, abutmentmeans presenting a shoulder in the path of travel of said pin at apredetermined distance from the eye of the needle to limit downwardmovement of said guided bar and spring means extending between a xedpoint in said machine head and said actuating means for biasing saidactuating means and said guided bar in inoperative position, and aexible cable or thc like extending around freely mounted rollersintermediate said guiding member and said manual operating means.

References Cited in the le of this patent UNITED STATES PATENTS 479,426Jenkins July 26, 1892 640,919 Kobler Jan. 9, 1900 2,544,577 Weber Mar.6, 1951

